It's right at 21 feet to the front corner where the lower front strap is in the front photo. I was worried more about the height of the cover with the addition of the front ultra breeze vent cover, but it fits well. I've had the cover since last fall, ended up storing her inside a warehouse over the winter, so we didn't use it then.
I've had it on about a month now, wanted to see how well it keeps it clean. I was surprised how easy it went on for the first time. Camping/ fishing trip next week, so I'll know how easy (or difficult) it is to take back off.
Not sure how different the box size for the TT's in the "23" series may be though.
2014 Roo 23SS
2013 GM Sierra CC
Prodigy P3 Brake Controller
Nites Camped 2016 -25